Pruebas diagnósticas en miastenia gravis. Conformación de un estándar diagnóstico mediante un método de consenso / Diagnostic test in myasthenia gravis. Creation of a standard for diagnosis using a method of consensus

Introducción. En la actualidad la mejor prueba para el diagnóstico de miastenia gravis (MG) es la electromiografía de fibra única (EFU). Debido al coste de la prueba, pocos hospitales en el mundo la pueden tener para uso rutinario para confirmar el diagnóstico de MG. Objetivo. Identificar un estándar de oro aceptable para hospitales que no cuenten de manera habitual con EFU mediante la utilización de una metodología de consenso realizado en tres etapas. Sujetos y métodos. Las dos primeras etapas del estudio se realizaron mediante encuestas prolectivas y la tercera etapa mediante una metodología Delfos. En la primera etapa se aplicó un instrumento a 55 neurólogos generales donde se preguntaba cuál era la mejor combinación de pruebas y la mejor prueba aislada con las que habitualmente realizaban el diagnóstico de MG. En la segunda etapa se aplicó un segundo instrumento de recolección a 15 expertos de unidad motora (EUM), quienes analizaron cuatro situaciones clínicas frecuentes en la práctica (cuadro clínico clásico de MG generalizada, paciente con cuadro de miastenia ocular, cuadro de MG generalizada de mediana probabilidad y cuadro clínico de baja probabilidad), identificando la mejor prueba aislada y el mejor conjunto de pruebas para el diagnóstico de miastenia gravis con y sin el uso de EFU. Finalmente, se crearon cuatro flujogramas de las cuatro situaciones clínicas analizadas que fueron consensuados mediante una metodología Delfos con ocho neurólogos EUM. Resultados. Hemos identificado un estándar de oro aceptable para hospitales que no cuenten de manera general con EFU mediante una metodología de consenso. También hemos consensuado cuatro flujogramas diagnósticos de las situaciones clínicas más frecuentes a las que nos enfrentamos en la práctica clínica habitual. Conclusión. Hemos encontrado una serie de resultados con una utilidad importante para el diagnóstico de MG aplicables a médicos generales, médicos internistas y neurólogos que no cuenten con todas las pruebas disponibles para el diagnóstico de esta enfermedad (AU)

[Diagnostic tests in myasthenia gravis. Creation of a standard for diagnosis using a method of consensus]. / Pruebas diagnósticas en miastenia gravis. Conformación de un estándar diagnóstico mediante un método de consenso.

INTRODUCTION: Nowadays the best test for the diagnosis of myasthenia gravis (MG) is the single fiber electromyography (SFEMG). Due to the cost of the test it has not become routine in most part of the hospitals to confirm the diagnosis of MG. OBJECTIVE: To identify an acceptable gold standard for hospitals which do not have access to SFEMG, but have access to some other classical test through the use of a consensus methodology. SUBJECTS AND METHODS: The study was realized in three stages. The first two stages were done through a prolective survey and the third stage through a Delfos methodology. During the first stage 59 general neurologist were interviewed, applying an instrument in which they were asked which were the best test and the best group of tests to diagnose MG without using the SFEMG. During a second stage, a second collection instrument was applied to 15 experts in motoneuron diseases to identify the best isolated test and the best test scheme with and without using the SFEMG in four frequent clinical situations in clinical practice (typical clinical case of generalized MG, patient with ocular myasthenia, patient with generalized MG of medium and low probability). Finally four flowcharts were created of the four analyzed clinical situations and were approved through a Delfos methodology with 8 neurologist motoneuron disease. RESULTS: We identified an acceptable gold standard for hospitals which do not have access to SFEMG through the use of a consensus methodology. We have also completed four diagnostic flowcharts about the most frequent clinical situations that we have faced in the ordinary practice. CONCLUSIONS: We have found a series of important results for the diagnosis of MG available to general physicians, internists and neurologist that do not have all the test for the diagnosis of MG.

[Prognosis of rotavirus diarrhea]. / Pronóstico de la diarrea por rotavirus.

OBJECTIVE: To compare the severity of rotavirus diarrhea (RV) and non-rotavirus diarrhea. MATERIAL AND METHODS: Between October 1994 and March 1995, a cross-sectional study was performed in 520 infants with acute diarrhea, at seven primary care level centers in five states of Mexico. Diagnosis of RV was done through immunoenzymatic assay or electrophoresis. Central tendency measures were used for data analysis. Results were presented as means and standard deviations, or median and variation. RESULTS: RV was isolated from 264 children; most of them were males aged 6 months to 1 year. Differences in clinical manifestations were statistically significant between the rotavirus-positive group and the rotavirus-negative group, in the following variables: median number of stools/24 hours; frequency of vomiting; temperature > 38 degrees C; dehydration; and clinical severity scoring. CONCLUSIONS: These results showed a poorer prognosis and a higher severity of rotavirus diarrhea, as compared to non-rotavirus diarrhea in infants.

Bloodborne viral infections in patients attending an emergency room in Mexico City: estimate of seroconversion probability in healthcare workers after an occupational exposure.

The frequency of hepatitis C (HCV), hepatitis B (HBV), human immunodeficiency virus (HIV), and human T-cell lymphotropic virus (HTLV) I/II was determined in the emergency room of a teaching hospital. Of 909 patients, 19% had at least one infection; 7.8% had HCV, 6.9% HBV, 3.3% HIV, and 2.8% HTLV I/II. The probability that a healthcare worker would have an accident with an infected patient and seroconvert was 4.99 to 24.9 per 100,000 venipunctures for HBV, 5.6 to 8.4 for HCV, and 0.12-0.16 for HIV in our emergency room.

Leukocyturia in women with diabetes and its clinical implications.

BACKGROUND: Urinalysis is one of the most common studies performed on the diabetic patient at every visit. The presence of leukocyturia is relatively common but it is not clear what the attitude of the physician toward this particular finding should be. The main objective of the present study was to investigate the clinical significance of leukocyturia in diabetic women. METHODS: Ninety-eight diabetic women (84.7% type 2) aged 57 +/- 13 years who were being seen at the diabetic out-patient clinic were randomly selected. All patients underwent a clinical and gynecologic examination and a urinalysis. A Papanicolaou smear and a urine culture were also obtained. RESULTS: The overall prevalence of leukocyturia (>5 cells/high power field (hpf)) was 46.5%. Patients with urinary tract infections (UTI) were 7.5 times more likely to have leukocyturia, while a leukocyte count <5cells/hpf predicted the absence of UTI in 96% of the women. In the comparison of patients with and without leukocyturia, we found that proteinuria (p = 0.06) and bacteriuria (p <0.002) were more common in the women with leukocyturia. A significant association with leukorrhea was not demonstrated. The empirical use of antibiotics was 12 times more frequent in the patients with leukocyturia. CONCLUSIONS: A urinary culture should be requested in all diabetic patients with leukocyturia. The possibility of a UTI is remote when leukocyturia is absent.

[An epidemic of primary bacteremia due to an endemic strain of Serratia marcescens in an intensive care unit]. / Epidemia de bacteremias primarias por una cepa endémica de Serratia marcescens en una unidad de terapia intensiva.

An outbreak of Serratia marcescens bacteremia detected in the intensive care unit (ICU) of a tertiary care center on the last days of October, 1985, is described. The rate of primary S. marcescens nosocomial bacteremia during the pre-epidemic period (January-September 1985) was 6.25 per cent; and for the post-epidemic period compared with the epidemic were significantly different (p < 0.0001). The outbreak strains belonged to the biotype A8b, which has been endemic in our hospital. The responsible organism exhibited an unusual antimicrobial resistance pattern associated to the presence of a specific plasmid (greater than 50 kilobases), which showed similar fragments after restriction endonuclease digestion. No specific risk factors were identified in the case-control study. The outbreak was probably related to a greater influx of infected patients, resulting in less careful infection control measures, due to the emergency situation which suffered the hospital after the earthquakes in 1985. The unusual high rate of blood isolation of S. marcescens at the ICU was the first sign of the outbreak. The prompt reinforcement of infection control policies facilitated its resolution.

[Efficacy of a rice-based beverage for the management of dehydration caused by acute diarrhea in children]. / Eficacia de una bebida a base de arroz en el manejo de la deshidratación por diarrea aguda en niños.

We tested the clinical efficacy of a rice-powder gruel (RPG) as an oral rehydration solution in a randomized clinical trial, comparing it with oral rehydration salts (ORS) prepared as recommended by WHO. RPG was prepared as mothers do it in a rural area, according to previous ethnographic work. RPG has sugar but no sodium or other electrolytes. Seventy patients under 5 years old with mild to moderate dehydration due to acute diarrhea were included in the trial. Ninety-two percent of children were successfully rehydrated with RPG and 91% of children were successfully rehydrated with ORS. Patients in the study group required less time to rehydrate and presented a reduction in fecal output as compared with the control group. We propose that the rice-powder gruel should find its place as a first line of treatment at the home level, when oral rehydration salts are not available, to prevent dehydration in the child affected with acute diarrhea, and that its use should be closely linked to no suspension or rapid reintroduction of oral feeding to provide an external source of sodium and other nutrients.

Dot-enzyme-linked immunosorbent assay (Dot-ELISA) of anti-Entamoeba histolytica antibodies in human serum and colostrum.

Seroepidemiologic and clinical studies of amoebiasis require improved methods for the detection and titration of anti-Entamoeba histolytica (Eh) trophozoite antibodies. We have developed a Dot-enzyme-linked immunosorbent assay (Dot-ELISA) to titrate anti-Eh antibodies in human serum and colostrum. The anti-Eh serum IgG antibody titers from healthy individuals and from patients with amoebic liver abscess obtained, with our Dot-ELISA were similar to those obtained with a standard ELISA, but the background values were lower. Significant anti-Eh sIgA antibody titers were found in seven out of 42 colostrum samples of mothers of newborn children with diarrhea. Our Dot-ELISA is rapid, inexpensive, and might be used for the diagnosis of individuals and in seroepidemiologic studies of amoebiasis.

[The use of beverages and food at home during acute infantile diarrhea: an ethnographic study in a rural Mexican area]. / Uso de bebidas y alimentos en el hogar durante la diarrea aguda del niño: estudio etnográfico en una zona rural mexicana.

A structured interview was applied through a personal interview to 142 peasant mothers aimed at exploring some beliefs about childhood diarrheal disease and the use of home-made beverages and feeding habits during the illness. The majority answered they used to give a herbal tea (90%) or a rice-based beverage (77%) to their child with diarrhea. Only 18% mentioned the use of oral rehydration packages. Sixty-three percent avoid certain foods while 25% withhold all food, usually for more than 24 hours, to a sick child. It is justified to assess the clinical efficacy of a rice-powder solution in the prevention of severe dehydration, as well as to promote an uninterrupted diet based on locally accepted and available foods, in the home management of a child with acute diarrhea.